1. Field of the Invention
The present invention relates to a scheduling method and system for guaranteeing real-time service quality of Wireless Broadband (WiBro) customer premises equipment (CPE).
2. Description of the Related Art
WiMAX (World Interoperability for Microwave Access, Inc.) is an organization founded in 2001 that promotes the IEEE 802.16 wireless broadband standard and provides certification for devices for compliant devices. WiMAX is designed to extend local Wi-Fi networks across greater distances such as a campus, as well as to provide last mile connectivity to an ISP or other carrier many miles away. In addition, Mobile WiMAX offers a voice and higher-speed data alternative to the cellular networks.
WiBro (Wireless Broadband) is the South Korean counterpart to Mobile WiMAX. Based on the IEEE 802.16e standard, South Korea leapfrogged the U.S. in long-range Wi-MAX connectivity as two companies launched WiBro in the summer of 2006. The initial services maintained a connection in vehicles moving as fast as 74 miles per hour within one kilometer of the tower.
A conventional terminal having a configuration of customer premises equipment (CPE) uses a single queue without detecting a real-time service channel established between a wide area network (WAN) and a local area network (LAN). Thus, quality of service (QoS) may be affected by change in situation of real-time data traffic and general data traffic.
Meanwhile, a system using a plurality of queues sets the bandwidth of a strict priority queue (SPQ) for a specific Internet protocol (IP)/port for real-time service according to a ratio in which simultaneous channels can be established for the total number of users, etc. However, customer premises equipment (CPE) is a general-purpose terminal rather than a terminal dedicated to real-time service, and thus a plurality of queues cannot be optimized and statically allocated.
Even when real-time service of customer premises equipment (CPE) is predicted, and queues are statically set according to channels, it is difficult to set an accurate bandwidth for each queue because a bandwidth that the queue must ensure is different according to a codec of a channel established between a WAN (wide are network) and a LAN (local area network).
In addition, algorithms, such as strict priority queue (SPQ), weighted round robin (WRR), etc., used in a system in which real-time service and general data service are mixed, give a priority order to queues to set an order of packets to be transmitted, and thus do not relate to ensuring a bandwidth needed for a real-time service channel.
A system using a conventional algorithm, such as strict priority queue (SPQ), weighted round robin (WRR), etc., assumes that a whole bandwidth is always fixed and thus is not appropriate for a bandwidth reservation policy in WiBro customer premises equipment (CPE) in which a bandwidth of a WAN (wide area network), which is a wireless section, changes according to distance from a radio access station (RAS), electric field strength, and surroundings.
Such a conventional customer premises equipment (CPE) has a problem in that it cannot support QoS when a terminal uses real-time service, such as voice over Internet protocol (VoIP), because terminals access the customer premises equipment (CPE) through a LAN (local area network) and perform communication via a WAN (wide area network).